/* flex */
%fc{
  display: flex;
}
%fw{
  @extend %fc;
  flex-wrap: wrap;
}
%ac{
  @extend %fc;
  align-items: center;
}
%cc{
  @extend %ac;
  justify-content: center;
}
%cr{
  @extend %ac;
  justify-content: right;
}
%sb{
  @extend %fc;
  justify-content: space-between;
}
%sa{
  @extend %fc;
  justify-content: space-around;
}
$flexs: fc, fw, ac, cc, cr, sb, sa;